i want to fix an home button for all activities.how?

i am designing an application which have diff types of functionalies through buttons/image buttons. At final the list might increase. i want to put one custom home button which always keeps on screen when i am in diff activities. or either if you have any idea about how this Home button is coded to this layout below screen. please help.

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Solution

Have you considered the Action Bar which is exactly designed for this purpose? http://developer.android.com/guide/topics/ui/actionbar.html